1. Field of the Invention
This invention relates to an improved leg exercise device which is easily configured for a variety of leg exercises and is adaptable for safe use by athletes of different size and strength. More particularly, it is concerned with a leg exercise device which incorporates an adjustable foot support, a variable positioning mechanism which adjusts the starting position of the weight-receiving unit, a yieldable frame interconnect which adapts the leg exercise device to athletes having different leg strengths, and a separable, adjustable bench which is easily configured for the desired exercise.
2. Description of the Prior Art
Exercise in general and weight lifting in particular has enjoyed a surge in popularity in recent years. Today, weight lifting is enjoyed by a wide variety of people in fitness centers, athletic programs, and strength and conditioning programs. In its infancy, such weight lifting programs typically used conventional free-weight barbells with the athlete using a variety of stances, or sometimes utilizing a specially configured support bench. Today, however, weight lifting programs have developed to a highly sophisticated state in which relatively complex devices are employed to enable the athlete to address and strengthen a particular muscle group.
This trend has led to the development of a number of leg exercise devices which are a substantial improvement over using barbell free weights to strengthen and condition the leg muscles. More recently, several leg exercise devices have been proposed which are adaptable for a variety of leg exercises. Typically, such devices have employed a floor-engaging frame, a pair of parallel, upwardly inclined rails fixedly secured to the frame, and a weight-receiving unit slidably mounted between the rails. With such a machine, a bench can be positioned at the base of the rails so that an athlete can lay in a supine position upon the bench, with his feet engaging the weight-receiving unit, and perform a leg press or power hip exercise by sliding the weight-receiving unit up the rails. In such a power hip exercise, substantially the same muscle groups are exercised as in a free weight squat utilizing traditional barbells, but the use of such a device substantially reduces stress on the lower back of an athlete thereby decreasing injury potential. Some of these leg exercise devices have been adaptable for removal of the bench and have incorporated shoulder-engaging pads on the weight-receiving unit. In such a configuration, the athlete may assume an anterior position (facing away from the weight-receiving unit) the athlete can perform a hack squat exercise, which is particularly useful in isolating and developing the quadricep muscles. In a posterior position (athlete facing the weight-receiving unit), and perform a power leg exercise, which is particularly useful in developing explosive leg power.
While such leg exercise devices have proven useful in many respect, a significant number of problems remain with such devices. For example, such devices have typically not incorporated structure for optimally supporting the feet of the athlete for both the hack squat exercise and the power leg exercise. As those skilled in the art will appreciate, it is important to properly support the balls of the feet of an athlete in the power leg exercise to achieve optimal conditioning of the calf muscles and achilles development. However, in the hack squat exercise, it is important that the entire foot of the athlete be supported and properly positioned to better isolate the quadricep muscles. A further problem associated with such past devices has been the inability to adjust the starting position of the weight-receiving unit upon the rails. Thus, it has been difficult to properly position the athlete upon such devices simply because such devices were not easily adaptable to various size and strengths of athletes.
Another problem sometimes encountered with such past leg exercise devices has been the binding or canting of the leg exercise unit as it slides up the rails. Particularly in rehabilitation programs, where one leg is weaker than the other leg, it is often difficult for an athlete to properly position his legs, particularly in the power hip exercise, where the leg exercise unit will slide without binding upon the rails. Still another difficulty associated with some past exercise devices is the positioning of the weights upon the weight-receiving unit. Typically such devices have incorporated one or more steel shafts secured to the weight-receiving unit for the sliding reception of the amount of free weights desired for the exercise. As can be appreciated, these shafts must be oriented upon the weight-receiving unit so that the free weights will not come off during exercise, even if the weight-receiving unit is suddenly released during exercise. For safety reasons, it is important that the steel shafts be oriented for retaining the free weights, however, sometimes the necessary orientation makes it very difficult to easily and quickly add or remove free weights.
A final problem often associated with such past leg exercise devices is their inability to easily be configured to provide adequate back support for both the hack squat exercise and the power hip exercise. As outlined above, it is desirable to provide back support during the power hip exercise to lessen the possibility of back stress during the exercise. Further, in the hack squat exercise, with the athlete in the anterior position, it is desirable to provide back support to the athlete. To provide back support in the hack squat exercise, it is necessary to incorporate the back support in the weight-receiving unit. A few of the past leg exercise devices have incorporated a permanent back support in the weight-receiving unit, however, such a built-in back support is undesirable for the power hip or power leg exercises. Further, such back supports have proven inadequate in providing the necessary support while nevertheless, making the weight-receiving unit cumbersome.